Electric meter.



w. H. PRATT & P. c. MGRGANTHALER.

Witnesses:

Patented Apr. 25,1916.

4 H Fig.3.

- 46, g 5 l I 25'. 7 f

Inventors: Wu Ham H'Pratt, Pete Gmor" anthaler,

TED STATES r WILLIAM' HQ PRATT, 0F LYNN, MASSACHUSETTS, AND PETER CQMORGANTHALER, OE

FORT WAYNE, INDIANA, ASSIGNORS T0 GENERAL ELECTRIC COMPANY, A CORPO- RATION OF NEW YORK.

ELECTRIC METER.

PatentedApr. 25, 1916.

. Application filed March 12, 1914. Serial No. 824,274.

T a all whom it may concern Be it known that we, VILLIAM H. PRATT, a citizen of the United States. residing at Lynn, county of Essex, State of l\'lassachusetts. and Pierre C. ilORG.-\NTIL \LER, a citizen of the l nited States, residing at Fort him-e specifically our invention relates to alternating current electric motor meters of the induction type. v i

The objects o'toui invention are to generally simplify and improve the construction 'of electric meters of the type to which our invention relates, and to provide a meter of high initial and sustained accuracy, of pleasing appearance, andsimple construction.

A further object of our invention is to provide an improved construction of electric meter inwhich the operative elements are easily and conveniently accessible for inspection, repair 'adj ustmcnt 'and testing.

other specific objects of our invention will be noted-in detail hereinafter.

The. features of our invention which we consider novel and patentablc are definitely pointed out in the claims appended hereto.

The novel features of our invention and the construction and operation of an electric motor of'the induction type'embodying these features will be understood from the following description taken in connection with the accon'ipanyiug drawings, in which; I

Figure 1 is a. front elcvationof the meter with thc covcr removed and the cover plate of the terminal chamber open; Fig. 2 is a. rear elevation of the motel" with the back plate removed; Fig. 3 is a sectional end elevation; Fig. this a perspective view ofthe friction compensating and phase lagging device employed in the meter; and F isa diagrammatic view of the electrical connections of the meter illustrating the operation. of our novel test loop.

Referring to Figs. 1, 2, and?) of thcjdrawings it will be seen-thatthe operative elements of the meter are mounted on a central supporting member 10 of magnetic material.

This supporting member is cast integrally with a cy1indr1ca1 member 11 and these two members form a compartment inclos ing'the magnetic circuit and motive elements of the meter. A terminal chamber 12 is. also in:

- tegrally cast with the supporting and cylin drical members. Posts 13 are secured to the supporting member 10 and serve in conjunction with the usual wing nuts to secure a suitable cover to the meter. The win nuts and cover are of the usual and well known types and for the sake of greater simplicity of the drawings have not been illustrated. The rear interiorwall of the cylindrical member 11 is provided with a shoulder 14 upon which rests a gasket 15 of felt or other suitable material. A back inclosing plate 16 is adapted to be securely held against the gasket 15 and shoulder 11 by means of three bolts 17 extending through holes 18 in the supporting membcr'lO. A key-holed supporting lug'7'2 of the usual type is cast integral with the cylindrical member 11. The base of the terminal chamber has two holes 71 through I which supporting screws are adapted to extend, so that these screws are inside the terminal chamber and inaccessible;

when this chamber is sealed.

The magnetic circuit of the meter comprises two separate and independent magnetic cores. One of these cores is substan-, tially rectangular in shape and has a center leg 1.9 and two outer legs 20. Thc'end of each outer leg extends inwardly toward the center leg, and the inwardly extending portion of each outer leg is separated from the center leg bvan air gap 21. A potential coil 2.4 is carried by the center leg 19 of this core. 'lhe,second magnetic core is U-shaped, as can be seen in Fig. 2 of the drawings, and has a current or series coil 22 mounted on each of its legs 23. The outside laminations of the U-shaped core are slit to provide tongues 70 which are bent over the coils 22 to firmly hold the Coils on the legs of the core, as will be clearly seen in Figs. 2 and 3 of the drawings. The coils 22 are connected in series by a conductor 71. Each of the two cores consists 'of a bundle of lami'- nations of magnetic material, as illustrated in Fig. 3 of the drawings. The laminations of each core are firmly bound together be-.

' substantially the. same plane. In order to secure the proper metertorquethe U core is of lesser. thickness than the rectangutween the two spacing frames whereby the two cores are united in a single unitary frames is also directly the compartment formed by cent, and directly in contact with,- each of the outside laminations of the rectangular shaped magnetic core. One of the spacing in contact with one of the outside laminations of the U-shaped magnetic core, whereby these corresponding outside laminations of the two'cores lie in shaped lar shaped core, and hence spacing bushings 26 of magnetic material are placed betweenv the other outside-lamination'of the U-shaped coreand the other spacing frame. Bolts 27 firmly bind the laminations of each core bestructurej constituting the magnetic circuit and motive elements of the meter. This unitary structure is mounted by means of bolts 28011 the supporting member 10 with the supporting member 1O andcylindrical Clamping members 7 5 of non-magnetic matenal further assist in firmly binding together the extremities of the legs of the potential core.

The spacing frames 25 serve the double function ofrigidly securing the two magnetic coresin a single unitary structure and of providing a return path of low and substantially uniform reluctance for the leakage potential flux. The leakage or torque producing potential flux passes from the po tential core to the series core across the air gap therebetween, and alarge part of this flux returns to the potential core through the magnetic spacing frames. here the iron of the meter casing is exclusively relied upon to form the return path for the potential leakage flux the reluctance may be unclesirably high and ununiform, due to imperfections in the materials or in the construction. The use of magnetic spacing frames in accordance with our invention eliminates both of these difficulties, since the reluctance of the spacing frames is substantially uniform I and relatively low.- The spacing frames, accordingly, provide a return path of lowand substantially uniform reluctance for the leakage potential flux, thereby increasing the torque of the meter and renderiiig its performance more definite,

Four main terminals 29 are arranged in the terminal chamber 12. The outside wall of the terminal chamber is provided with four holes 30, and the oppositely positioned wall of the chamber is provided with four registering holes 31. One end of each termina l 29 extends through one of the holes 31 and is provided with a binding screw 32. The other end of each terminal has a recess anemben 11'.

33 in which an electric conductor, such as a leadingein-wire, is adapted to be firmly secured by a screw 84. The potential and series coils are adapted to be suitably connected by means of conductors and the binding screws 32 to the terminals.

Referring to Fig. 5' of the drawings it will be seen that one end of the potential coil 24 is directly connected to one of the main terminals 29. The other end of thepotential coil is connected to'an auxiliary terminal 35. The auxiliary terminal and a cooperating auxiliary terminal 36 are arranged in the terminal chamber, as shown in Figs. 1 and 2 of the drawings. The auxiliary terminal 36 is electrically con nected to one of the main terminals 29. A. metallic strip or test loop 37 is arranged to connect or disconnect at will the auxiliary terminals. This strip has a slot 38 which registers with the terminal 36 and a recess adapted to register with the terminal 35 when one end of the slot 38 is moved adjacent the terminal 36, which position of the striptis illustrated in Fig. 1 of the drawingsr The strip 37 has a projecting linger 39 by which it is conveniently moved.

It will be observed, by reference to Figs. 1 and 5 oil the drawings, that by moving the test loop 37 and disconnecting the auxiliary terminals 35 and 36 the potential coil is electrically cut out of circuit with the mains 40 and also disconnected from the series coils. This is a particularly-archantageous feature in testing the meter. For example, where a number of meters are being tested in series the potential coils are disconnected by means of the test loop 37, and their the potential coil of each meter is connected to the-standard voltage, thus eliminating the error occasioned by the voltage drops in the various meters. Again, where an installed meter is to be tested, the potential coil can be electrically disconnected from the series coils by meansof the test loop, and then connected by means of one inaiirterminal 2!) and the auxiliary terminal directly across the main line conductors. A load box, comprising a transformer with a low voltage secondary of well known construction, can then be employed to furnish the testing current to the series 'coils of the meter, thus avoiding the necessity of using line voltage and regulating resistances for supplying the testing current to' the current coils.

-Bushings -ll of insulating material are arranged in the openings 30 of the terminalv chamber and have holes which register with the recesses 33 of the tern'1inals. The main terminals and the auxiliary terminals are firmly embedded in a mass of insulating maa ter al 42 which is molded in position In the terminhl chamber. v The insulating matev ral may consist of any of the well known her,

molded insulating. material,

.moved from'the chamber except by disintegrating the insulating..m aterial.

A disk armature 43 of aluminum or other suitable material is secured ,to a rotatably mounted shaft 44. The shaft 44 has a lower step bearing 45 operati-vely mounted on the supporting member 10 and an upper bearing 46' also mounted on the supporting memher. The shatte is operatively geared to a meter register 47; The construction of I the meter register and gearing operatively with the supporting member 10.

-tively engages a 5O ture. The plate has bent lugs an attaching member 58.

' in the application connectingit to the meter shaft'constitute no part of our present invention, but these features are described in detail and claimed for patent of Alexander J. R. Fiego, Serial No. 825,998, filed March 20,1914? r r A-bra'cket 48 extends from and is integ irial 1e bracket has a centrally extending slot 49. The rotation of the armature is adapted to be damped or retarded by two permanent magnets 50,- which are rigidly secured together by a yoke 51 of non-magnetic material. The yoke is adjustably mounted on the bracket 48, and is in its adjusted position by means of setscrews 52 extending through the slot 49 and engaging suitable screw-threaded holes in the'yoke. The: damping magnets are providedsvith a micrometer adjusting attachment comprising a right hand and left hand screw-threaded bolt 53 which when turned moves the magnetsand yoke bodily with respect to the disk armature. One of the screw-tlncaded ends of the bolt operascrew-threaded hole in a lug 54 preferably integral with the supporting plate 10 The other end of the bolt 53 has .an oppositely pitched screw-thread which engaged a screw-threaded hole of the yoke 51. By a suitable selection of the pitch of. the screw-threads on the bolt 53 an adjustment ot-any desired degree can be ob-v tained; v

3k figetion compensating plate for obtaining 'th light load adjustment of the meter extends in the air gap between the two magnetic cores and parallel to the disk arma- 57 secured to member has a bent adapted to be secured.

The attaching lug 59. An adjusting, bolt 61 passesthrougha screw-threaded hole in a boss (30 integrally attached to the supportingplate 10, and is secured at its inner end to the lug 59, as shown in Fig. 1 ot the drawings. The serves as a means for adjusting the position of the combined friction compensating and phase lagging device with respect to the poles of the magnetic cores. The attaching plate is provided with slots (32. through which extend set-screws (33; the latter or; gaging in scrcw-thrcadcd holes in the supporting-member ll) and serving to rigidly secure thc't'riction compensating plate in its adjusted position.

The friction compensating plate 56 is proadjusting bolt thusvided with a [substantialtv rectanguhlr hole 64'. A portion of the plate G7), on one side of the holeol is ofi'set. This otl'set portion (:5 is provided with a slot (iii extending in a short distance from the outside edge; substantially rectangular phase-lagging plate.

67 is positioned in the hole (34.- and is provided witha set screw b8 which extends through the slot (36, whereby the position of the'plate (37 can, be adjusted with respect to the. plate 66 and the two platcs secured together in the adjusted position. The offset of the portion ()5 'is such that the surfaces of the friction compensating plate it) and phase lagging plate ()7 lie in substantially the same planes. as will be best seen in Fig. 4 of the drawings. The phase laggiug plate is so adjusted that the desired phasc lag of degrees between. the series and potential fluxes is obtained. as will be. understood by those skilled in the art.

The friction compensating plate is prel erably constructed of. German sil\'er,- brass or similar metallic material. while the phasc lagging plate is preferably constructed of a metallic material having a higl'ror specific conductivity than the material of the friction compensating plafx as for example. copper oralun'iinum. T to resistance of the lag plate is thus lower than that of the triction compensating plate and a sullicicut range of lag adjustment is thereby insuredv The friction con'ipcnsating plate o'f'course produces a certain phase. lag". but it is do sirablc to roducc'tlu, greaterpart of the. phase lag by the phase lagging plate and this is accomplished by maliing the resist ance of the phase lagging plate lower than that of the friction compensating plate. It will be obviousthat the desired ditterenc in resistance of the two plates may be secured by properly proportioning the dimensions of the two plates may be constructed of the same metallic material. The construction of the plates of dissimilar metallic materials of different specific resistances together with proper proportioning of the dimensions of the plates aii'ords, howcyerfa more satisfactory and convenient means for securing the and thus the two plates light-load rotation of the disk armature.

' by rigidly and proper friction compensation and phase lag adjustment.

The mounting of the phase lagging plate on the friction compensating plate results in a single unitary structure which is convenient of access, easily adjusted, and occupies little space in the air gap between the magnetic cores. The adjusting bolt 61 is very conveniently positioned in front of the sup porting member 10; and is readily accessible when the cover of'the meter is removed, as illustrated in Fig. 1 of the drawings. Legends Sand F are stamped on the lug 59 to indicate the proper direction to turn the adjusting bolt (31 to produce a slower or fastler t will be obvious that the phase lagging plate need not necessarily be adjustable, since it is possible to so design and mount this plate that its resistance and position with respect -to the friction compensating plate produce the desired phase lag.

The theory and method of operation of our improved construction of meter will be readily understood by those skilled in the art. It will be observed that we have provided a compact induction meter in which the operative elements are easily accessible and conveniently removable for inspection and repair. All necessary adjustments can be made without difficulty and with a minimum disassembling of the meter. The number of parts in the meter is few and these are secured to a central supporting member, Wherefore there is less diliiculty involved in securing proper alinement of the parts, and less danger that the meter will get out of alinement during transportation. The embedding of the terminals in a molded insulating compound is a decided improvement in electric meters. The terminals are therepermanently positioned in the chamber, and the only Way in, which they can be removed from the chamber is by chipping out or disintegrating the insulating compound.

While various features of our invention are herein described in. connection with an induction meter, it will be evident to those skilled in the art that the practical applications of these features are in no way limited or restricted to this particular type of electric meter. Numerous modifications and changes in the details of construction and in the application of our invention to various types of electric meters will be apparent to those skilled in the, art. We do not, therefore, Wish to limit our invention to the specific application or details of c0nstruction hereih illustrated and described by Way of example, but we aim in the appended claims to cover all applications and modifications of the features oi our invention within the spirit and scope thereo' What we claim as new and desire to sea core of magnetic income cure by Letters Patent oi? the United 1s:-

1. in an. alternating current motor met-er,

States,

aininations, second and independent core of magnetic laminations, and two frames of magnetic material rigidly united with said two cores in a single unitary structure and forming a path for lines of magnetic force from one core to the other core.

2. In an alternating current motor meter, a core of magnetic laminations, a second and independent core or magnetic laminations, and two frames of magnetic material be tween which the laminations of each core are firmly bound together, said frames serving to unite the two cores in a single unitary structure constituting of the meter.

3. In an alternating current motor meter, a core of magnetic laminations, a second and independent core of magnetic laminations, a frame of magnetic material in magnetic connection with the outer laminations on. each side of both cores and forming a.

the other core, and means rigidly securing said cores and frames together to form a single unitary structure constituting tlfe magnetic circuit of the meter.

4. In an alternating current motor meter, 9. core of magnetic laminations, a second and independent core of magnetic laminations, and two parallel frames each comp .ng a continuous strip of magnetic material be tween which the laminations of each core are firmly bound together, said frames thus each core are mechanically bound together thereby uniting the two cores in a single unitary structure constituting the magnetic circuit and motive elements of the meter.

6. In an alternating current motor meter, a core of laminated magnetic material, apotential coil in operative relation to said. core, a second core of laminated magnetic material, a current coil in operative relation to said second core, and two parallel frames each comprising a continuous strip of mag netic material between which the laminations of each core arefirmly bound together thereby forming a rigid unitary structure constituting the magnetic circuit and Zl'l0- tive elements of the meter.

'2. In an alternating current motor meter, a core of laminated magnetic material havthe magnetic circuitv path for lines of magnetic :torce irom one core to v ing a center leg and two outer legs separated at their ends from the center leg by air gaps, a potential coil on the center leg, at second and independent core of laminated magnetic material havingtwo legs positioned opposite said air gaps, a current coil on each of the legs of the second core, and frames of magnetic material rigidly united with said 7 two cores in a unitary structure and forming a path for lines of magnetic force from having its two legs positioned substantially opposite said air gaps, a current coil on each leg of said U-shaped core, frames of magnetic material adjacent the outer laminations of each core, and means rigidly securing the laminations of the cores between said spacing frames thereby forming a unitary structure constituting the magnetic circuit and motiye elements of the meter.

9. In an alternating current motor meter, a core of magnetic laminations, a second and independent core ofmagnetic laminations, a frame ofmagnetic material in contact with the outer laminations on .one side of both cores and forming a path' for lines of magnetic force from one core to the other core, and means rigidly securing said cores and said frame together to form a single unitary structure constituting the magnetic circuit of the meter.

10. In an electric motor meter, a supporting member, a rotatably mounted disk armature, a bracket extending from said mem her and integral therewith, a pair of per-L manent magnets, a yoke of non-magnetic material rigidly securing said magnets together and adapted to be mounted on said bracket whereby said magnets are positioned to retard the rotation of said disk armature,

a bolt operatively engaging said yoke and said member and adapted when turned to adjust the position of said magnets with respect to said disk armature, and-means for securing said yoke-to said bracket.

11. In an electric motor meter, a supporting member, aLdisk armature rotatably mounted thereon, a bracket extending from said mem her and having a slot therein, a pair of l A n permanent magnets, a yoke of non-magnetic 'material rigidly securing said magnets'together, said yoke having a screw-threaded hole adapted to register with said slot whereby said magnets are positioned to retard the rotation of said disk armature, a bolt operatively engaging said yoke and said member and adapted when turned to adjust the posi-' tion of said magnets With respect to, said disk armature, and a set-screw extending through the slot in said bracket and engaging the screw-threaded hole in said yoke and adapted to secure the yoke and magnets in adjusted position.

' 12. l n an alternating current motor meter, a supporting member of magnetic material, a' disk armature extending through said member and rotatably supported ;.thereby, motive elements mounted on one side of said member and positioned to exert a.turning torque on said disk armature, a'bracket extending from the other side of said member and integral therewith, a pair of permanent magnets, a yoke of non-ma'gnetic -material rigidly securing said magnets together and adapted to be mounted on said bracket whereby said magnets are positioned to retard the rotation of said disk armature, 0. lug integral with said member,-a bol't;operatively related to said lug and to said yoke and adapted when turned to adjust the position of said magnets with respect to said disk armature, and'means for securing said yoke to said bracket.

13. In an electric motor meter, a rotatable disk armature, a pair of permanent magnets adapted to retard the rotationof the armature, a yoke of nonmagnetic material rigidly securing said magnets together, a fixed bracket upon which said yoke and. magnets are adapted to be mounted, and a bolt having a screw-thread at one end ,operatively engaging a fixed part of the meter and an oppositely pitched screw-thread at the other end operatively engaging said yoke whereby the position of said magnets with respect to said armature can be adjusted by turning said bolt. i

14. In an alternating current motor meter,

a supporting member of magnetic material,

and so that the magnets are positioned toretard the rotation of said armature, a lug integral with said member and having, a scre\\-'-threaded hole therein, abclt having a screw-thread at 'oneend engaging in the screw-threaded hole' of said lug and an oppositely pitched screw-thread at the 'other end engaging in the other screw-threaded holeof said yoke whereby the turning of said bolt serves to adjust the position of said ma nets with respect to said armature,

and a set screw extending through said slot and engaging the registering screw-threaded hole of said yoke and adapted to secure the yoke and magnets in their adjusted positions.

15. In an alternating current motor meter, a substantially rectangular core of laminated magnetic material having a center leg and two outer legs separated at their ends from the center leg by air gaps, a potential coil carried by said center leg, a U-shaped core of laminated magnetic material being of lesser thickness than that of the rectangular coreand having its two legs positioned substantially opposite said air gaps, a current coil on each leg of said U-shaped core, a frame of magnetic material adjacent the outer laminations on one side of each of said cores and positioned so'that such outer laminations are in substantially the same plane, a'second frame of magnetic material adjacent the other outer lamination of said rectangular shaped core, spacing means of magnetic material between said second frame and the other outer lamination of the U- shaped core, and means rigidly securing the laminations of each core between said frames.

.16. In an .alternatingcurrent motor meter, :1 core of laminated magnetic material, a second core of laminated magnetic material, a magnetic frame comprising a continuous strip of magnetic material, and means rigidly securing said cores and said frame together as a single unitary structure constituting the magnetic circuit of the meter whereby said frame forms a path for lines of magnetic force from one core to the other core.

In Witness whereof I, the said WILLIAM H. Pnarr, have 5th day of March, 1914, and I, the said PETER C. MORGANTHALER, have hereunto set my hand this 9th day of March, 1914.

WILLIAM H. PRATT. PETER C. MORGANTHALER. Witnesses to Pratt:

Join: A. MoMANUs, J12, Ronnnr SHAND.

Witnesses to Morganthaler:

R. R. ENOCH,

D. W. Cruse.

hereunto set my hand this 

